Verticillium Wilt, a Primer

Jocularity aside for just a moment, my innate Master Gardener side has come out and demands an opportunity to educate. So please bear with her and she'll eventually get bored and go away...

This is a picture of a thus far healthy Canada Red Chokeberry tree. Notice the full crown and the lush foliage.

And now we have its 'brother'. This tree was planted in the same year (9 years ago). Notice the thin crown and the smaller leaves. Verticillium wilt is a naturally occurring virus in the soil that migrates into a susceptible host where the fungus effectively clogs the xylem tissues (the water way) of the affected plant. As a result, essential nutrients are unavailable to the host plant and it will eventually die.

Effective Diagnosis can be obtained by pruning a plant that is suspected to be infected. Streaking or a dark ring can be found in the cross section of the wood. For more information, please refer to articles such as this.

Unfortunately, at this time there is no cure for this disease and the offending organisms can and will remain in the soil for many years to come. The only recourse is to plant resistant specimens in the area and to practice good hygiene (it's always good to sanitize one's tools between tending to different plants) in regards to pruning and trimming plants and trees.